WordPress PHP Warning: simplexml_load_file()

Question

I'm facing the following error in my WordPress Site

[03-Sep-2017 10:12:36 UTC] PHP Warning:  simplexml_load_file():  in /home/syriacar/public_html/syria-cart.com/wp-content/plugins/polylang/modules/wpml/wpml-config.php on line 53

and here is the file error content

    foreach ( $plugins as $plugin ) {
        if ( file_exists( $file = WP_PLUGIN_DIR . '/' . dirname( $plugin ) . '/wpml-config.xml' ) && false !== $xml = simplexml_load_file( $file ) ) {
            $this->xmls[ dirname( $plugin ) ] = $xml;
    }
    }

Answer 1

It might be due to malformed wpml-config.xml file.

For example, on this support WordPress forum page, you can find a similar issue and the cause was missing </key> closing tag before </admin-texts>.

UPDATE:

In your comments, you also mention yith-woocommerce-af‌​filiates warning, so another possibility is that the YITH WooCommerce Affiliates plugin doesn't have the wpml-config.xml or is empty.

The polylang documentation about wpml-config.xml mentions the following:

Developpers must place the wpml-config.xml file in the root directory of the plugin or theme.